Non-destructive testing may be used to test parts. By using non-destructive testing, properties of a material of the part may be analyzed without causing damage to the material. Certain non-destructive testing is performed using interferometry. Interferometry uses superposition to combine waves from a single source to provide information. In some instances, interferometry uses a laser light directed toward a surface area of an object. The laser light may take different paths before returning to a detector. The detector may determine a result relating to the surface area of the object. The result may be analyzed to determine whether there is a defect in the object.
Generally, multiple laser beams may be used with multiple interferometers. However, multiple laser beams, from different sources, may lead to inaccurate results.